Strategies to reduce plate waste in primary schools – experimental evaluation

To determine and compare the effect of two interventions in reducing the plate waste of school lunches. A between-group analysis was conducted among children from three primary schools: (i) a group receiving intervention A, designed for children and focusing on nutrition education and food waste; (ii) a group receiving intervention B, intended for teachers and focusing on the causes and consequences of food waste; and (iii) a control group with no intervention. For each child, physical weighing of individual meals and leftovers was performed on three non-consecutive weeks at baseline (T0), 1 week (T1, short term) and 3 months (T2, medium term) following the intervention. Plate waste was recorded for a total of 1742 lunches during 14 d over eight different menus. Portuguese public primary schools in the city of Porto. All fourth-grade children (n 212) attending the three preselected schools. After intervention A focusing on nutrition education designed for children, a decrease in soup waste was observed compared with the control group. The effect was greater at T1 (-11·9 (se 2·8) %; P